Entertaining misadventures of a four year old boy named Caillou, where each day he discovers something new and interesting with his mommy, daddy, and Rosie. Between Caillou segments are segments featuring Caillou's pet cat Gilbert, Caillou's teddy bear, Teddy, and Caillou's toy dinosaur, Rexy, in puppet form. The show deals with issues like fear of the dark, patience, being a good friend, being a good sibling, and other important facts of life.